1. Field of the Invention
The invention relates to a scanning device for carrying out three dimensional scanning of dental models, to a sliding panel therefor, and to a method therefor.
2. The Prior Art
The extraoral scanning of dental impressions or models made from dental impressions with stationary scanning devices is disclosed in the prior art. The object to be scanned is usually larger than the range of image detection of the image detecting unit. It is therefore necessary to create images of the object to be scanned in several segments and to reposition the image detecting unit relatively to the object to be scanned for each image.
A device for determining the shape of a duplicate that contains a clamping device, a sensor contrivance, and a data storage unit, and in which the clamping device and the sensor contrivance are movable relatively to each other, is disclosed in EP 0 913 130 A1.
The individual images are joined together by means of software correlation. In this process, the software attempts to find the same identifying points in two different images and thereby establish a position relationship between the images. Due to imaging properties and other software-related inaccuracies incurred during the software correlation, errors cannot, in practice, be avoided when joining two correlated images. In the worst case, these errors can summate when a series of images are joined together.
Furthermore, the technical computation requirements for correlating images with unknown misalignment are very great, which results in a long processing time.
It is thus an object of the invention to provide a scanning device, as well as a method of scanning dental models, that permits rapid and exact scanning of dental models and is in addition cheap to produce in comparison with prior art devices.